1. Technical Field
The disclosure relates to a speaker device. More particularly, relates to a multi-directional flat speaker device.
2. Background
The two most direct sensory systems of human being are visual and audible systems, so for a long time, scientists try their best to develop related elements or system techniques. The demand of providing the user with more plentiful or specific sound fields by utilizing the composition of speaker system will be consistent in the future market application. Recently, electro-acoustic speakers are mainly classified into direct and indirect radiating types, and are approximately classified into moving coil, piezoelectric, and electrostatic speakers according to driving manners. The moving coil speaker is currently the most commonly used and most mature product. However, a moving coil speaker cannot be compressed due to the physical structure thereof. Accordingly, moving coil speaker is not suitable for 3C products and home entertainment systems which have their sizes reduced constantly. A piezoelectric speaker pushes a membrane to produce sounds based on the piezoelectric effect of an electrical material (i.e., the material is deformed when an electric field is supplied thereon). Although having a compressed and small structure, the piezoelectric speaker can not be flexible as the electrical material requires sintering.
Currently, the manufacture of speakers still applies the design production method as that for a single unit as illustrated in U.S. Pat. No. 3,894,199.
As for the electrostatic speaker, for example, in U.S. Pat. No. 3,894,199, an electro-acoustic transducer structure is mainly provided, as shown in FIG. 1. The structure includes two fixed electrode structures 110 and 120 placed on two sides. The fixed electrode structures 110 and 120 have a plurality of pores for scattering the sounds generated. A vibrating film 130 is disposed between the fixed electrode structures 110 and 120. A fixing structure 140 is made of an insulation material, and used to fix the fixed electrode structures 110 and 120 and the vibrating film 130. The fixed electrode structures 110 and 120 are respectively connected to an AC source 160 through a transformer 150. When an AC signal is transmitted to the fixed electrode structures 110 and 120, a potential is alternately changed to enable the vibrating film 130 to generate vibration due to difference potentials on two sides thereof, and thereby generating corresponding sound. However, the above configuration needs to enhance the sound-pressure output, so an additional power element is required to work together with the driving process. In this manner, the apparatus not only has a large volume, but more elements are used, and the cost is also relatively high. In addition, the fixing structure 140 must fix the fixed electrode structures 110 and 120 and the vibrating film 130, so the electro-acoustic transducer structure cannot achieve the flexible characteristics.